A library of dependency-free utilities that do just do one thing.
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README.md

Just πŸ’

Build Status

A library of zero-dependency npm modules that do just do one thing. A guilt-free alternative to those bulkier utility libraries. Ideal for mobile web development or wherever bytes are precious.

Jump To API

We welcome contributions. Please follow our contribution guidelines.

Read πŸ“š

Try 🍦

A REPL for every utility (powered by RunKit)

Browser Support πŸ’»

Data based on available saucelabs test browsers. It's likely Just is also fully supported by some older versions not verifiable via saucelabs.

Chrome Safari Firefox IE/Edge Node Mobile Safari Android
yes yes yes IE9+ 6+ iOS 8+ Android OS 5+

The Modules πŸ“¦

just-diff-apply

🍦Try It

npm install just-diff-apply

Apply a diff object to an object. Pass converter to apply a http://jsonpatch.com standard patch

  import diffApply from 'just-diff-apply';

  const obj1 = {a: 3, b: 5};
  diffApply(obj1,
    [
      { "op": "remove", "path": ['b'] },
      { "op": "replace", "path": ['a'], "value": 4 },
      { "op": "add", "path": ['c'], "value": 5 }
    ]
  );
  obj1; // {a: 4, c: 5}

  // arrays
  const obj3 = {a: 4, b: [1, 2, 3]};
  diffApply(obj3, [
    { "op": "replace", "path": ['a'], "value": 3 }
    { "op": "replace", "path": ['b', '2'], "value": 4 }
    { "op": "add", "path": ['b', '3'], "value": 9 }
  ]);
  obj3; // {a: 3, b: [1, 2, 4, 9]}

  // nested paths
  const obj4 = {a: 4, b: {c: 3}};
  diffApply(obj4, [
    { "op": "replace", "path": ['a'], "value": 5 }
    { "op": "remove", "path": ['b', 'c']}
    { "op": "add", "path": ['b', 'd'], "value": 4 }
  ]);
  obj4; // {a: 5, b: {d: 4}}

  // using converter to apply jsPatch standard paths
  // see http://jsonpatch.com
  import {diffApply, jsonPatchPathConverter} from 'just-diff-apply'

  const obj2 = {a: 3, b: 5};
  diffApply(obj2, [
    { "op": "remove", "path": '/b' },
    { "op": "replace", "path": '/a', "value": 4 }
    { "op": "add", "path": '/c', "value": 5 }
  ], jsonPatchPathConverter);
  obj2; // {a: 4, c: 5}

just-compare

🍦Try It

npm install just-compare

import compare from 'just-compare';

// primitives: value1 === value2
// functions: value1.toString == value2.toString
// arrays: if length, sequence and values of properties are identical
// objects: if length, names and values of properties are identical
compare([1, [2, 3]], [1, [2, 3]]); // true
compare([1, [2, 3], 4], [1, [2, 3]]); // false
compare({ a: 2, b: 3 }, { a: 2, b: 3 }); // true
compare({ a: 2, b: 3 }, { b: 3, a: 2 }); // true
compare({ a: 2, b: 3, c: 4 }, { a: 2, b: 3 }); // false
compare({ a: 2, b: 3 }, { a: 2, b: 3, c: 4 }); // false
compare([1, [2, { a: 4 }], 4], [1, [2, { a: 4 }]]); // false
compare([1, [2, { a: 4 }], 4], [1, [2, { a: 4 }], 4]); // true
compare(NaN, NaN); // true

just-clone

🍦Try It

npm install just-clone

import clone from 'just-clone';

// Deep copies objects and arrays, doesn't clone functions

var arr = [1, 2, 3];
var subObj = { aa: 1 };
var obj = { a: 3, b: 5, c: arr, d: subObj };
var objClone = clone(obj);
arr.push(4);
objClone.d.bb = 2;
obj; // {a: 3, b: 5, c: [1, 2, 3, 4], d: {aa: 1}}
objClone; // {a: 3, b: 5, c: [1, 2, 3], d: {aa: 1, bb: 2}}

just-pluck-it

🍦Try It

npm install just-pluck-it

import pluck from 'just-pluck-it';

pluck([{ a: 1, b: 2 }, { a: 4, b: 3 }, { a: 2, b: 5 }], 'a'); // [1, 4, 2]
pluck({ x: { a: 1, b: 2 }, y: { a: 4, b: 3 }, z: { a: 2, b: 5 } }, 'a'); // {x: 1, y: 4, z: 2}

just-flush

🍦Try It

npm install just-flush

import flush from 'just-flush';

flush([1, undefined, 2, null, 3, NaN, 0]); // [1, 2, 3, NaN, 0]
flush([true, null, false, true, [null], undefined]); // [true, false, [null], true]
flush({ a: 2, b: null, c: 4, d: undefined }); // {a: 2, c: 4}
flush('something'); // undefined
flush(); // undefined

Objects

just-extend

🍦Try It

npm install just-extend

import extend from 'just-extend';

var obj = {a: 3, b: 5};
extend(obj, {a: 4, c: 8}); // {a: 4, b: 5, c: 8}
obj; // {a: 4, b: 5, c: 8}

var obj = {a: 3, b: 5};
extend({}, obj, {a: 4, c: 8}); // {a: 4, b: 5, c: 8}
obj; // {a: 3, b: 5}

var arr = [1, 2, 3];
var obj = {a: 3, b: 5};
extend(obj, {c: arr}); // {a: 3, b: 5, c: [1, 2, 3]}
arr.push(4);
obj; // {a: 3, b: 5, c: [1, 2, 3, 4]}

var arr = [1, 2, 3];
var obj = {a: 3, b: 5};
extend(true, obj, {c: arr}); // {a: 3, b: 5, c: [1, 2, 3]}
arr.push(4);
obj; // {a: 3, b: 5, c: [1, 2, 3]}

extend({a: 4, b: 5}); // {a: 4, b: 5}
extend({a: 4, b: 5}, 3); {a: 4, b: 5}
extend({a: 4, b: 5}, true); {a: 4, b: 5}
extend('hello', {a: 4, b: 5}); // throws
extend(3, {a: 4, b: 5}); // throws

just-values

🍦Try It

npm install just-values

import values from 'just-values';

values({ a: 4, c: 8 }); // [4, 8]
values({ a: { aa: 2 }, b: { bb: 4 } }); // [{aa: 2}, {bb: 4}]
values({}); // []
values([1, 2, 3]); // [1, 2, 3]
values(function(a, b) {
  return a + b;
}); // []
values(String('hello')); // []
values(1); // throw exception
values(true); // throw exception
values(undefined); // throw exception
values(null); // throw exception

just-entries

🍦Try It

npm install just-entries

import entries from 'just-entries';

// Object:
entries({ c: 8, a: 4 }); // [['c', 8], ['a', 4]]
entries({ b: { bb: 4 }, a: { aa: 2 } }); // [['b', {bb: 4}], ['a', {aa: 2}]]
entries({}); // []

// Array:
entries([{ c: 8 }, { a: 4 }]); // [[0, {c: 8}], [1, {a: 4}]]
entries(['Γ€', 'mauvais', 'ouvrier', 'point', 'de', 'bon', 'outil']);
// [[0, 'Γ€'], [1, 'mauvais'] ... [6, 'outil']]
entries([]); // []

just-pick

🍦Try It

npm install just-pick

import pick from 'just-pick';

var obj = { a: 3, b: 5, c: 9 };
pick(obj, ['a', 'c']); // {a: 3, c: 9}
pick(obj, 'a', 'c'); // {a: 3, c: 9}
pick(obj, ['a', 'b', 'd']); // {a: 3, b: 5}
pick(obj, ['a', 'a']); // {a: 3}

just-omit

🍦Try It

npm install just-omit

import omit from 'just-omit';

var obj = { a: 3, b: 5, c: 9 };
omit(obj, ['a', 'c']); // {b: 5}
omit(obj, 'a', 'c'); // {b: 5}
omit(obj, ['a', 'b', 'd']); // {c: 9}
omit(obj, ['a', 'a']); // {b: 5, c: 9}

just-is-empty

🍦Try It

npm install just-is-empty

import isEmpty from 'just-is-empty';

isEmpty({ a: 3, b: 5 }); // false
isEmpty(['a', 'b']); // false
isEmpty({}); // true
isEmpty([]); // true
isEmpty(null); // true
isEmpty(undefined); // true

just-is-circular

🍦Try It

npm install just-is-circular

import isCircular from 'just-is-circular';

const a = {};
a.b = a;
isCircular(a); // true

const a = {};
a.b = { c: a };
isCircular(a); // true

const a = {};
a.b = { c: 4 };
isCircular(a); // false

const a = [];
a.push(a);
isCircular(a); // true

isCircular({}); // false
isCircular('hi'); // false
isCircular(undefined); // false

just-is-primitive

🍦Try It

npm install just-is-primitive

import isPrimitive from 'just-is-primitive';
isPrimitive('hi'); // true
isPrimitive(3); // true
isPrimitive(true); // true
isPrimitive(false); // true
isPrimitive(null); // true
isPrimitive(undefined); // true
isPrimitive(Symbol()); // true
isPrimitive({}); // false
isPrimitive([]); // false
isPrimitive(function() {}); // false
isPrimitive(new Date()); // false
isPrimitive(/a/); // false

just-filter-object

🍦Try It

npm install just-filter-object

import filter from 'just-filter-object';

// returns a new object containing those original properties for which the predicate returns truthy
filter({ a: 3, b: 5, c: 9 }, (key, value) => value < 6); // {a: 3, b: 5}
filter({ a1: 3, b1: 5, a2: 9 }, (key, value) => key[0] == 'a'); // {a1: 3, a2: 9}
filter({ a: 3, b: 5, c: null }, (key, value) => value); // {a: 3, b: 5}

just-map-object

🍦Try It

npm install just-map-object

import map from 'just-map-object';

// DEPRECATED: use just-map-values
map({ a: 3, b: 5, c: 9 }, (key, value) => value + 1); // {a: 4, b: 6, c: 10}
map({ a: 3, b: 5, c: 9 }, (key, value) => key); // {a: 'a', b: 'b', c: 'c'}
map({ a: 3, b: 5, c: 9 }, (key, value) => key + value); // {a: 'a3', b: 'b5', c: 'c9'}

just-map-values

🍦Try It

npm install just-map-values

import map from 'just-map-values';

// predicate updates values, recieves (value, key, obj)
map({ a: 3, b: 5, c: 9 }, value => value + 1); // {a: 4, b: 6, c: 10}
map({ a: 3, b: 5, c: 9 }, (value, key) => value + key); // {a: 3a, b: 5b, c: 9c}
map({ a: 3, b: 5, c: 9 }, (value, key, obj) => obj.b); // {a: 5, b: 5, c: 5}

just-map-keys

🍦Try It

npm install just-map-keys

import map from 'just-map-keys';

// predicate updates keys, recieves (value, key, object)
map({ a: 'cow', b: 'sheep', c: 'pig' }, value => value);
// {cow: 'cow', sheep: 'sheep', pig: 'pig'}
map([4, 5, 6], (value, key) => key + 1); // {1: 4, 2: 5, 3: 6}
map({ a: 3, b: 5, c: 9 }, (value, key) => key + value); // {a3: 3, b5: 5, c9: 9}
map({ a: 3, b: 5, c: 9 }, (value, key, obj) => obj.b + value + key);
// {'8a': 3, '10b': 5, '14c': 9}

just-reduce-object

🍦Try It

npm install just-reduce-object

import reduce from 'just-reduce-object';

// applies a function against an accumulator and each key-value pairs of the object
// to reduce it to a single value
reduce(
  { a: 3, b: 5, c: 9 },
  (acc, key, value, index, keys) => {
    acc[value] = key;
    return acc;
  },
  {}
); // {3: 'a', 5: 'b', 9: 'c'}

reduce({ a: 3, b: 5, c: 9 }, (acc, key, value, index, keys) => {
  acc += value;
  return acc;
}); // 17

just-safe-get

🍦Try It

npm install just-safe-get

import get from 'just-safe-get';

const obj = { a: { aa: { aaa: 2 } }, b: 4 };

get(obj, 'a.aa.aaa'); // 2
get(obj, ['a', 'aa', 'aaa']); // 2

get(obj, 'b.bb.bbb'); // undefined
get(obj, ['b', 'bb', 'bbb']); // undefined

get(obj.a, 'aa.aaa'); // 2
get(obj.a, ['aa', 'aaa']); // 2

get(obj.b, 'bb.bbb'); // undefined
get(obj.b, ['bb', 'bbb']); // undefined

get(null, 'a'); // null
get(undefined, 'a'); //undefined

const obj = { a: {} };
const sym = Symbol();
obj.a[sym] = 4;
get(obj.a, sym); // 4

just-safe-set

🍦Try It

npm install just-safe-set

import set from 'just-safe-set';

const obj1 = {};
set(obj1, 'a.aa.aaa', 4}); // true
obj1; // {a: {aa: {aaa: 4}}}

const obj2 = {};
set(obj2, [a, aa, aaa], 4}); // true
obj2; // {a: {aa: {aaa: 4}}}

const obj3 = {a: {aa: {aaa: 2}}};
set(obj3, 'a.aa.aaa', 3); // true
obj3; // {a: {aa: {aaa: 3}}}

// don't clobber existing
const obj4 = {a: {aa: {aaa: 2}}};
set(obj4, 'a.aa', {bbb: 7}); // false

const obj5 = {a: {}};
const sym = Symbol();
set(obj5.a, sym, 7); // true
obj5; // {a: {Symbol(): 7}}

just-typeof

🍦Try It

npm install just-typeof

import typeOf from 'just-typeof';

typeOf({}); // 'object'
typeOf([]); // 'array'
typeOf(function() {}); // 'function'
typeOf(/a/); // 'regexp'
typeOf(new Date()); // 'date'
typeOf(null); // 'null'
typeOf(undefined); // 'undefined'
typeOf('a'); // 'string'
typeOf(1); // 'number'
typeOf(true); // 'boolean'

just-flip-object

🍦Try It

npm install just-flip-object

import flip from 'just-flip-object';

// flip the key and value
flip({ a: 'x', b: 'y', c: 'z' }); // {x: 'a', y: 'b', z: 'c'}
flip({ a: 1, b: 2, c: 3 }); // {'1': 'a', '2': 'b', '3': 'c'}
flip({ a: false, b: true }); // {false: 'a', true: 'b'}

Arrays

just-unique

🍦Try It

npm install just-unique

import unique from 'just-unique';

unique([1, 2, 3, 2, 3, 4, 3, 2, 1, 3]); // [1, 2, 3, 4]

var a = { a: 3 };
var b = { b: 4 };
var c = { c: 5 };
unique([a, a, b, c, b]); // [a, b, c]

unique([1, '1', 2, '2', 3, 2]); // [1, '1', 2, '2', 3]

// declaring sorted array for performance
unique([1, 1, '1', 2, 2, 5, '5', '5'], true); // [1, '1', 2, 5, '6']

// declaring strings array for performance
unique(['a', 'c', 'b', 'c', 'a'], false, true); // ['a', 'b', 'c']

just-flatten-it

🍦Try It

npm install just-flatten-it

import flatten from 'just-flatten-it';

flatten([[1, [2, 3]], [[4, 5], 6, 7, [8, 9]]]);
// [1, 2, 3, 4, 5, 6, 7, 8, 9]

just-index

🍦Try It

npm install just-index

import index from 'just-index';

index([{ id: 'first', val: 1 }, { id: 'second', val: 2 }], 'id');
// {first: {id: 'first', val: 1}, second: {id: 'second', val: 2}}
index([{ id: 'first', val: 1 }, null], 'id'); // {first: {id: 'first', val: 1}}
index([], 'id'); // {}
index([], null); // throws
index({}, 'id'); // throws

just-insert

🍦Try It

npm install just-insert

import insert from 'just-insert';

insert([1, 2, 5, 6], ['a', 'c', 'e'], 2); // [1, 2, 'a', 'c', 'e', 5, 6]
insert([1, 2, 5, 6], 'a', 2); // [1, 2, 'a', 5, 6]
insert([1, 2, 5, 6], ['a', 'c', 'e'], 0); // ['a', 'c', 'e', 1, 2, 5, 6]
insert([1, 2, 5, 6], ['a', 'c', 'e']); // ['a', 'c', 'e', 1, 2, 5, 6]

just-intersect

🍦Try It

npm install just-intersect

import intersect from 'just-intersect';

intersect([1, 2, 5, 6], [2, 3, 5, 6]); // [2, 5, 6]
intersect([1, 2, 2, 4, 5], [3, 2, 2, 5, 7]); // [2, 5]

just-compact

🍦Try It

npm install just-compact

import compact from 'just-compact';

compact([1, null, 2, undefined, null, NaN, 3, 4, false, 5]); // [1, 2, 3, 4, 5]
compact([1, 2, [], 4, {}]); // [1, 2, [], 4, {}]
compact([]); // []
compact({}); // throws

just-last

🍦Try It

npm install just-last

import last from 'just-last';

last([1, 2, 3, 4, 5]); // 5
last([{ a: 1 }, { b: 1 }, { c: 1 }]); // {c: 1}
last([true, false, [true, false]]); // [true, false]
last([]); // undefined
last(); // throws
last(null); // throws
last(undefined); // throws

just-tail

🍦Try It

npm install just-tail

import tail from 'just-tail';

tail([1, 2, 3, 4, 5]); // [2, 3, 4, 5]
tail([{ a: 1 }, { b: 1 }, { c: 1 }]); // [{b: 1}, {c: 1}]
tail([true, false, [true, false]]); // [false, [true, false]]
tail([]); // []
tail(); // throws
tail(null); // throws
tail(undefined); // throws

just-random

🍦Try It

npm install just-random

import random from 'just-random';

random([1, 2, 3]); // one of [1, 2, 3], at random

just-shuffle

🍦Try It

npm install just-shuffle

import shuffle from 'just-shuffle';

shuffle([1, 2, 3]); // array with original elements randomly sorted
shuffle([1]); // [1]
shuffle(); // throws
shuffle(undefined); // throws
shuffle(null); // throws
shuffle({}); // throws

just-split

🍦Try It

npm install just-split

import split from 'just-split';

split([]); // []
split([1, 2, 3, 4, 5]); // [[1, 2, 3, 4, 5]]
split([1, 2, 3, 4, 5, 6, 7, 8, 9], 3);
[[1, 2, 3], [4, 5, 6], [7, 8, 9]];
split(['a', 'b', 'c', 'd', 'e'], 2);
[['a', 'b'], ['c', 'd'], ['e']];
split([1, 2, 3, 4, 5, 6, 7, 8], 3);
[[1, 2, 3], [4, 5, 6], [7, 8]];
split({}, 3); // throws
split(null, 3); // throws
split([1, 2, 3, 4, 5, 6], '3'); // throws

just-split-at

🍦Try It

npm install just-split-at

import splitAt from 'just-split-at';

splitAt([1, 2, 3, 4, 5], 2); // [[1, 2], [3, 4, 5]]
splitAt([{ a: 1 }, { b: 1 }, { c: 1 }], -1); // [[{a: 1}, {b: 1}], [{c: 1}]]
splitAt([], 2); // [[], []]
splitAt(null, 1); // throws
splitAt(undefined, 1); // throws
splitAt([1, 2, 3, 4, 5], {}); // throws

just-partition

🍦Try It

npm install just-partition

import partition from 'just-partition';

partition([1, 5, 2, 4, 3], n => n > 3); // [[5, 4],[1, 2, 3]]
partition(['a', 2, 3, '3'], x => typeof x == 'string'); // [['a', '3'],[2, 3]]
partition([1, 2, 3, 4], x => typeof x == 'number'); // [[1, 2, 3, 4],[]]
partition([1, 2, 3, 4], x => typeof x == 'string'); // [[], [1, 2, 3, 4]]
partition([], n => n > 3); // [[], []]
partition({ a: 1, b: 2 }, n => n > 1); // throws
partition(null, n => n > 1); // throws
partition(undefined, n => n > 1); // throws

just-range

🍦Try It

npm install just-range

import range from 'just-range';

range(1, 5); // [1, 2, 3, 4]
range(5); // [0, 1, 2, 3, 4]
range(-5); // [0, -1, -2, -3, -4]
range(0, 20, 5); // [0, 5, 10, 15]

just-remove

🍦Try It

npm install just-remove

import remove from 'just-remove';

remove([1, 2, 3, 4, 5, 6], [1, 3, 6]); // [2, 4, 5]

just-union

🍦Try It

npm install just-union

import union from 'just-union';

union([1, 2, 5, 6], [2, 3, 4, 6]); // [1, 2, 3, 4, 5, 6]

just-zip-it

🍦Try It

npm install just-zip-it

import zip from 'just-zip-it';

zip([1, 2, 3]); // [[1], [2], [3]]
zip([1, 2, 3], ['a', 'b', 'c']); // [[1, 'a'], [2, 'b'], [3, 'c']]
zip([1, 2], ['a', 'b'], [true, false]); // [[1, 'a', true], [2, 'b', false]]
zip([1, 2, 3], ['a', 'b'], [true]); // [[1, 'a', true], [2, 'b', undefined], [3, undefined, undefined]]
zip(undefined, {}, false, 1, 'foo'); // throws
zip([1, 2], ['a', 'b'], undefined, {}, false, 1, 'foo'); // throws

Strings

just-template

🍦Try It

npm install just-template

import template from 'just-template';

const data = {
  a: {
    aa: {
      aaa: 'apple',
      bbb: 'pear'
    },
    bb: 'orange'
  },
  b: 'plum'
};
template(
  '2 ${a.aa.aaa}s, a ${a.aa.bbb}, 3 ${a.bb}s and a ${b}. Yes 1 ${a.aa.bbb}.',
  data
);
// '2 apples, a pear, 3 oranges and a plum. Yes 1 pear.'

just-truncate

🍦Try It

npm install just-truncate

truncate('when shall we three meet again', 9); // 'when s...'
truncate('when shall we three meet again', 12, ' (etc)'); // 'when s (etc)'
truncate('when shall we', 15); // 'when shall we'
truncate('when shall we', 15, '(more)'); // 'when shall we'
truncate('when shall we', 10, ' (etc etc etc)'); // ' (etc etc etc)'

just-prune

🍦Try It

npm install just-prune

  prune('when shall we three meet again', 7); // 'when...'
  prune('when shall we three meet again', 7, ' (more)'; // 'when (more)'
  prune('when shall we', 15,); // 'when shall we'
  prune('when shall we', 15, ' (etc)'); // 'when shall we'
  prune('when shall we', 7, ' (more)'); // ' (more)'

just-squash

🍦Try It

npm install just-squash

squash('the cat sat on the mat'); // 'thecatsatonthemat'
squash(' the cat sat on the mat '); // 'thecatsatonthemat'
squash('\tthe cat\n sat \fon \vthe \rmat '); // '\tthecat\nsat\fon\vthe\rmat'
squash('\tthe cat\n sat \fon \vthe \rmat ', true); // 'thecatsatonthemat'
squash(
  `the cat
sat on the mat`,
  true
); // thecatsatonthemat

just-left-pad

🍦Try It

npm install just-left-pad

leftPad('hello', 9); // '    hello'
leftPad('hello', 3); // 'hello'
leftPad('hello', 9, '.'); // '....hello'
leftPad('hello', 9, '..'); // '....hello'
leftPad('hello', 10, 'ab'); // 'bababhello'
leftPad('hello', 9, '\uD83D\uDC04'); // 'πŸ„πŸ„πŸ„πŸ„hello'
leftPad('hello', 10, '\uD83D\uDC11\uD83D\uDC04'), // 'πŸ„πŸ‘πŸ„πŸ‘πŸ„hello'
  leftPad('hello', 7, 'πŸ„'), // 'πŸ„πŸ„hello'
  leftPad(null, 7); // throws
leftPad([], 4, '*'); // throws
leftPad('hello', 4, true); // throws
leftPad('hello', -4, true); // throws
leftPad('hello', 2.3, true); // throws

just-right-pad

🍦Try It

npm install just-right-pad

rightPad('hello', 9); // 'hello    '
rightPad('hello', 3); // 'hello'
rightPad('hello', 9, '.'); // 'hello....'
rightPad('hello', 9, '..'); // 'hello....'
rightPad('hello', 10, 'ab'); // 'helloababa'
rightPad('hello', 9, '\uD83D\uDC04'); // 'helloπŸ„πŸ„πŸ„πŸ„'
rightPad('hello', 10, '\uD83D\uDC11\uD83D\uDC04'), // 'helloπŸ‘πŸ„πŸ‘πŸ„πŸ‘'
  rightPad('hello', 7, 'πŸ„'), // 'helloπŸ„πŸ„'
  rightPad(null, 7); // throws
rightPad([], 4, '*'); // throws
rightPad('hello', 4, true); // throws
rightPad('hello', -4, true); // throws
rightPad('hello', 2.3, true); // throws

just-camel-case

🍦Try It

npm install just-camel-case

camelCase('the quick brown fox'); // 'theQuickBrownFox'
camelCase('the_quick_brown_fox'); // 'theQuickBrownFox'
camelCase('the-quick-brown-fox'); // 'theQuickBrownFox'
camelCase('theQuickBrownFox'); // 'theQuickBrownFox'
camelCase('behold theQuickBrownFox'); // 'beholdTheQuickBrownFox'
camelCase('Behold theQuickBrownFox'); // 'BeholdTheQuickBrownFox'
camelCase('thequickbrownfox'); // 'thequickbrownfox'
camelCase('the - quick * brown# fox'); // 'theQuickBrownFox'
camelCase('theQUICKBrownFox'); // 'theQUICKBrownFox'

// `strict` lower cases anything not at the beginning of a word
// and the very first letter
camelCase('theQuickBrownFox', { strict: true }); // 'thequickbrownfox'
camelCase('behold theQuickBrownFox', { strict: true }); // 'beholdThequickbrownfox'
camelCase('Behold theQUICKBrownFox', { strict: true }); // 'beholdThequickbrownfox'

just-kebab-case

🍦Try It

npm install just-kebab-case

kebabCase('the quick brown fox'); // 'the-quick-brown-fox'
kebabCase('the-quick-brown-fox'); // 'the-quick-brown-fox'
kebabCase('the_quick_brown_fox'); // 'the-quick-brown-fox'
kebabCase('theQuickBrownFox'); // 'the-quick-brown-fox'
kebabCase('theQuickBrown Fox'); // 'the-quick-brown-fox'
kebabCase('thequickbrownfox'); // 'thequickbrownfox'
kebabCase('the - quick * brown# fox'); // 'the-quick-brown-fox'
kebabCase('theQUICKBrownFox'); // 'the-q-u-i-c-k-brown-fox'

just-snake-case

🍦Try It

npm install just-snake-case

snakeCase('the quick brown fox'); // 'the_quick_brown_fox'
snakeCase('the-quick-brown-fox'); // 'the_quick_brown_fox'
snakeCase('the_quick_brown_fox'); // 'the_quick_brown_fox'
snakeCase('theQuickBrownFox'); // 'the_quick_brown_fox'
snakeCase('theQuickBrown Fox'); // 'the_quick_brown_Fox'
snakeCase('thequickbrownfox'); // 'thequickbrownfox'
snakeCase('the - quick * brown# fox'); // 'the_quick_brown_fox'
snakeCase('theQUICKBrownFox'); // 'the_q_u_i_c_k_brown_fox'

just-pascal-case

🍦Try It

npm install just-pascal-case

pascalCase('the quick brown fox'); // 'TheQuickBrownFox'
pascalCase('the_quick_brown_fox'); // 'TheQuickBrownFox'
pascalCase('the-quick-brown-fox'); // 'TheQuickBrownFox'
pascalCase('theQuickBrownFox'); // 'TheQuickBrownFox'
pascalCase('thequickbrownfox'); // 'Thequickbrownfox'
pascalCase('the - quick * brown# fox'); // 'TheQuickBrownFox'
pascalCase('theQUICKBrownFox'); // 'TheQUICKBrownFox'

Numbers

just-clamp

🍦Try It

npm install just-clamp

import clamp from 'just-clamp';

var n = 5;
clamp(1, n, 12); // 5
clamp(3, n, 1); // 3
clamp(8, n, 9); // 8
clamp(0, n, 0); // 0

var n = -5;
clamp(1, n, 12); // 1
clamp(-7, n, -8); // -7

clamp(NaN, n, 8); // NaN
clamp(3, n, NaN); // NaN
clamp(3, NaN, 8); // NaN

clamp(undefined, n, 8); // throws
clamp(3, n, 'h'); // throws
clamp(3, false, 8); // throws

just-modulo

🍦Try It

npm install just-modulo

import modulo from 'just-modulo';

modulo(7, 5); // 2
modulo(17, 23); // 17
modulo(16.2, 3.8); // 17
modulo(5.8, 3.4); //2.4
modulo(4, 0); // 4
modulo(-7, 5); // 3
modulo(-2, 15); // 13
modulo(-5.8, 3.4); // 1
modulo(12, -1); // NaN
modulo(-3, -8); // NaN
modulo(12, 'apple'); // NaN
modulo('bee', 9); // NaN
modulo(null, undefined); // NaN

Functions

just-compose

🍦Try It

npm install just-compose

import compose from 'just-compose';

const sqRootBiggest = compose(Math.max, Math.sqrt, Math.trunc);
sqRootBiggest(10, 5); // 3
sqRootBiggest(7, 0, 16); // 4

just-curry-it

🍦Try It

npm install just-curry-it

import curry from 'just-curry-it';

function add(a, b, c) {
  return a + b + c;
}
curry(add)(1)(2)(3); // 6
curry(add)(1)(2)(2); // 5
curry(add)(2)(4, 3); // 9

function add(...args) {
  return args.reduce((sum, n) => sum + n, 0);
}
var curryAdd4 = curry(add, 4);
curryAdd4(1)(2, 3)(4); // 10

function converter(ratio, input) {
  return (input * ratio).toFixed(1);
}
const curriedConverter = curry(converter);
const milesToKm = curriedConverter(1.62);
milesToKm(35); // 56.7
milesToKm(10); // 16.2

just-demethodize

🍦Try It

npm install just-demethodize

const demethodize = require('just-demethodize');

const trimFn = demethodize(''.trim);
['hello ', ' goodbye', 'hello again'].map(trimFn);

just-flip

🍦Try It

npm install just-flip

import flip from 'just-flip';

flip(console.log)(1, 2, 3); // 2, 1, 3

just-partial-it

🍦Try It

npm install just-partial-it

import partial from 'just-partial-it';

const cubedRoot = partial(Math.pow, _, 1 / 3);
cubedRoot(64); // 4

const getRoot = partial(Math.pow, 64);
getRoot(1 / 2); // 8

just-debounce-it

🍦Try It

npm install just-debounce-it

import debounce from 'just-debounce-it';

const fn1 = debounce(() => console.log('Hello'), 500);
fn1();
fn1();
fn1();
// 500ms later logs 'hello' once

const fn2 = debounce(() => console.log('Hello'), 500, true);
fn2(); // logs hello immediately
fn2();
fn2();
// 500ms later logs 'hello' once

just-throttle

🍦Try It

npm install just-throttle

import throttle from 'just-throttle';

const fn1 = throttle(() => console.log('hello'), 500, true);
setInterval(fn1, 400);
// logs 'hello' immediately and then every 500ms

const fn2 = throttle(() => console.log('hello'), 500);
setInterval(fn2, 400);
// logs 'hello' after 500ms and then every 500ms

just-once

🍦Try It

npm install just-once

import once from 'just-once';

const fn = once(() => console.log('hello'));

fn();
// logs 'hello'
fn();
// does nothing

Testing

Run all tests as a single test suite with

npm run test

Cross browser tests (via saucelabs) are in the sauce branch

Contribute!

https://github.com/angus-c/just/blob/master/CONTRIBUTING.md